feat(configurator): fp.pricing.rule — formula-based pricing engine with complexity surcharges

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

fusion-plating/fusion_plating_configurator/models/__init__.py

@@ -6,3 +6,6 @@
 from . import fp_treatment
 from . import fp_part_catalog
 from . import fp_coating_config
+from . import fp_pricing_complexity_surcharge
+from . import fp_pricing_rule
+from . import sale_order